Tensioning device for yarn throwing machines of the up-twister type



H. LASCH .TENSIONING' DEVICE FOR YARN THROWIR IG MACHINES OF THE UPTWISTER TYPE Filed 001;. -16, 1943 2 Sheets-Sheet 1 Oct. 24, 1944. sc 2,361,041 TENSIONING DEVICE FOR YARN THBOWING MACHINES OF THE UP-TWISTER TYPE Y Filed Oct. 16, 1943 2 Sheets-Sheet 2 Patented Oct. 24, 1944 'TENSIONING DEVICE FOR YARN THROWING MACHINES OF THE. UP-TWISTER Tyre Herbert Lasch, Withington, Manchester, England Application October 16, 1943, Serial No. 506,496

In Great Britain October 16, 1942 5'Claims. (01. 57106) This invention relates to the tensioning devices of yarn throwing machines of the up-twister type, in which a yarn (for example a continuous .filament yarn) is led-endwise from a vertically-disposed bobbin by a fiyer rotatable on the axis of the bobbin, then upwards through a balloon guide, further upwards to a glass or like guide rod, and from thence through a suitable traverse guide to a cheese or equivalent receiver.

In practice, the balloon guide requires to be accurately spaced with respect to the upper end of the bobbin and to the fiyer above the bobbi in order to impart just the correct length and tension to the balloon. However, since the diam-.

eter of the wound bobbin-varies as the yarn is drawn off, the tension in the balloon, and consequently in the yarn above the balloon is varied. Also, as the point of unwinding of the yarn moves from the top to the bottom of the bobbin, there is a consequent variation of the tension in the yarn. This has meant that, for a given machine,

with a given spindle speed and gauge of flyer,

and with a given type of yarn, the maximum and minimum diameters of the wound bobbins, the

number of turns on the bobbin for each traverse of the guide and the spindle speeds have been restricted, since for any given position of the balloon guide the maximum spindle speed, andthe range of efiiciency amongst the several variables is flxed. g

In the event of the tension becoming too small, the twist will be imparted to theyarn unevenly,

- which will cause snarls and consequent weakness, and these snarls may pass on to the cheese, impair the quality of the twisted yarn. and give trouble in later operations. in the event of the tension becoming too great. it may result in over-stretching of the yarn, also with consequent weakness, even if actual breakage does not occur. Although these two extremes may be avoided by proper choice and soting of the above-mentioned variables, the variation of the tension due to the difference of the diameters of the package on the bobbin during the process, and due to the traverse length of the bobbin still remain, and cause unevenness in the twist imparted to the yarn, with consequent variation in the tensile strength, this defect being particularly obvious with the coarser counts. This unevenness results also in a varying shrinkage factor and a varying afiinity to dyestuffs in the ultimate woven or knitted fabtics in the finishing processes, since dur ng the wet treatments, the difierently-tensioned por- On the other hand,

tions of, the yarn seek to recover their respective original molecular conditions. -With a fixed balinvention aims at overcoming all these difliculties automatically, by arranging for variations in the.

loon guide, the supply package or bobbin has to be wound very accurately and fairly hard, and during such winding operation the yarn mustbe kept under considerabletension, which again may cause stretching. Any soft layers, loose yarn ends, or protruding filaments, may tend to catch the balloon during the throwing operation and increase the tension dangerously to the breaking point. For the above reasons, yarns containingfilaments of certain staples have not hitherto been processed successfully on machines of the up-twisti-ng type.

Thenew tensioning device according to this tension in the yarn to be automatically cor-' rected, and in such a manner that not only the increased tension in the yarn which has gonelforward, and in which the increase originated, is relieved, but also any increased tension in the balloon is reduced to normal so as not to affect the on-coming yarn.

The accuracy of the winding of the supply bobbin is therefore no longer. of such importance, and the use of this invention will permit also of the throwing of staple fibre yarns in an up-twister machine. Further, the receiver cheese or bobbin will, because of this invention, be wound with an even tension throughout the twisting operation,

' resulting in a perfectly-wound package.

, the yarn against the influence of counter-wei ht The main advantages therefore are, evenlyimpartedtwist resulting in a high average of tensile strength due to the even tensioning of the yarn, as well as a greater range of the abovementioned variables, of which the most'important one is the possibility of using larger supply packages. The improved tensioning device can also be used successfully for any type of overend winding where the control of the balloon area is essential for maintaining evenness of tension during the winding process.

According to this invention. in the throwin of yarns on an up-twister throwing machine, the yarn coming from the supply packa e and fiver is caused to pass through two movable gu d s a ranged to give it a substant al deflect on. and o e of which functions as a balloon guide: the nosi-.

tionof the gu des (and therefore the am nt 0* deflection) being deter ined by the t i n f means; and so that any increase of tens on moves one guide towards the stra ghtenedmutpnsiti n of the yarn so as to diminish the angle of deflec- Ill described below.

tion and in so doing relieves the tension in the such balloon guide and the aforesaid glass rod both the guides being overbalanced by a common counterweight, but being capable of yielding under any increased tension of the yarn; the latter to lessen the degree of deflection in the yarn and thus allow a short extra, length to go forward to relieve the increased tension in the foregoing yarn, where it originated, and the former to reduce the tension again,.back to normal, by moving towards the bobbin.

According to a further feature of the invention,,the counterweight is. so mounted that between its possible extreme .positions it passes through a position ofmaximum effect, By this arrangement the total .tensioning effect of the guides on the yarn cannot exceed a pre-determined amount, and moreover, begins to fall again as the balloon guide approaches its lowest position, nearest the flyer.

In the accompanying drawings one example of the invention is illustrated:

Fig. l is aside elevation of the device (with its support in cross section), the "minimum-tension position of the device being shown in full lines, with certain portions'shown in a greatertensionv position in broken lines;

Fig. 2 is a similar view to Fig, 1, but with full lines showing the parts in a greater-tension porier member," and at its forward end is bent first upwardly at I2, then rearwardly at I 3 and laterally at ll, andthis last portion is formed with a pig-tail loop Ii.

Pivotally mounted on the pin I is the member III which is a bifurcated bracket having a short lateral bush Illa on the side nearest the carrier member, and below which passes the wire I I of the balloon guide. This bracketcarries the other yarn guide I6 extending upwardly behind the said transverse bar a: of the machine, and then laterally (see Fig. 3) having a wide pigtail loop I1 at its upper end ofwhich the centre is in line with the pigtail l5 of the balloon guide. Fixed to the same'bracket l 0 is a further wire l8 which extends forwardly and at its front end has a wide lateral loop I! serving as a support for the long wire VII of the balloon guide. This wire l8 also extends rearwardly from the bracket I 0, being bent downwards at an angle to its forward part, and the'lower end carries a counterweight 20 which also is bifurcated and clips on to the wire H being adiustablealong such wire, thus determining the efl'ectual amount of counterweight. The weight is held in thetadjusted position by the screw 2|. The bracket III has two parallel openings across the central gap, to locate respectively the wire l8 and the lower end of the fixed uide I, which latter is curled around the wire [8. 1

In use, with the parts in the position shown in full lines in Fig. l, the lower yarn guide II has 'sition, and certain portions shown in the minimum-tension position in broken lines; and

Fig. 3 is a plan.

In the drawings, there is a carrier member I.

made for example of a zinc alloy diecasting, and comprising a shorter forwardly-extending portion 2 and a longer rearwardly-extending portion 3. The forwardly-extending portion 2 forms the upper Jaw of a clamp; and has on its top side a vertically-extending member 4, serving as a temporary holder to receive the flyer and the spindle button when they are removed from the spindle, say for the changing of a bobbin. The rearwardly-extending portion 3 is inclined downwardly at an angle to the forwardly-extending portion 2, and is formed atits lower end with a lateral extension or boss I, having a hole 0 which forms a pivot for one of the guides as hereinafter mentioned.

This carrier member I is secured to one of the usual transverse bars a: of the machine, by means of the forwardly-extending portion 2 and an attached member 6 which forms the lower Jaw of the clamp, the two jaws being connected together .by the pivot pin 1, and being clamped on to the rod 2: by the screw and nut 8. Tightening or the screw 8 causes the Jaws to bind on the pin! and hold it, but split pins 8 are passed through-it as I an additional safeguard against endwise movement. Also mounted on the pin 7 is a member The movable guide (1. e. the balloon guide) H isof stainless steel wire. and is pivotally mounted by its rear end in the lateral extremity or boss I of the rearwardly-extending part 8 of the ca"- its pig-tail loop I! a certain distance above the position which would beoccupied by the usual fixed balloon guide, whilst the pig-tail loop I! of the other yarn guide is behind the plane of the said transverse bar a: ofthe machine, so that there is a substantial deflecti'onin the yarn between the lower guide and the usual glass guide rod (not shown) at the upper part of the machine. A The counterweight 20 should be adjusted in such a way that it gives-at its maximum eifect (-i. e. slightly above the horizontal position of wire II) the required predetermined tension to the thread. I Q

Should the-tension in the yarn increase, for

I any reason, the upwardly-extending guide l6 will be pulled forward and thereby partly straighten out the deflection in the yarn, and also, by displacing the support l9 at the forward end of wire l8 (owing to rotation of bracket III on pin 1) causesthe balloon guide IE to move downward by its own weight. Sincethe length of yarn between the balloon guide I! and the glass rod in this straightened-out position is less than that length when the guides are in original position, the difference represents a temporary extrasupply t0- the receiver package which will be sufficient to relieve the tension in the yarn which passed forward immediately before the change took place, whilst the downwardly moving balloon guide I! will, to some extent, shorten the balloon area, and bring the tension in the on-coming yarn back to normal.

I The actual form of each of the guides, and of their respective supports, of the counter-weight one spot, whilst in the upper guide the thread will traverse from side to side.

What I 'claim is: 1. A yarn-tensioning otal movements shorten and lengthen the balloon, a further pivotally-mounted guide moving in a path substantially at right angles to the path of .the balloon guide, and a single counterbalance means for the two guides tending to maintain them in relative positions which substantially deflect the yarn, the movements of the further guide being such as to lessen the deflection of the yarn as the balloon guide shortens the balloon and to increase the deflection of the yarn as the balloon, guide lengthens the balloon.

2. A yam-tensioning device for a yarn throw ing machine comprising a carrier member adapt ed to be fixedly held to a fixed part of the machine, a balloon guide pivotally mounted in thecarrier member, a bracket pivotally supported on the carrier member, means on such bracket forming a support for the balloon guide, counterweight means carried by the bracket and a further yarn guide carried by the pivoted bracket, the two guides being moved simultaneously by the counterweight to positions where they substantially deflect the yarn, passing through them, and being moved against the counterweight to positions where they lessen the deflection of the yarn, andsimultaneously shorten the balloon.

3. A yarn-tensioning device for a yarn threwing machine'comprisi'ng a carrier member having at its forward end one jaw of a clamp and extending rearwardly therefrom, a further .elamp jaw device for a yarn throwing machine comprising a pivotally-mounted ba1-' loon guide mounted so. that its to-and-fro pivextending rearwardly, and a counterweight adjustable on the rearward extension of the supporting member tending to return both guides topositions where they increase the deflection of the yam'as the balloon is lengthened.

4.'In a yarn-tensioning devicefor a yarn throwing machine, a yarn guide, a counterweight and a support for a balloon guide, all connected together for simultaneous pivotal movement," a carrier member pivotally carrying the said parts, and a balloon guide resting on said support, the balloon guide being pivotally mounted in thefl'said carrier member and arranged so that as it moves I down to shorten the balloon the two guides ap'- pivotaily connected;to the carrier member and; I with the first jaw, adapted to grip a fixed part of the machine, a, balloon guide pivotally mounted in-the rear-end of the carrier member and e3- tending forwardly thereof so as to rise and fall to lengthen and shortenthe balloon, a bifurcated ,bracket pivotally -rnounted on one side of the carrier member, a yarn guide held in the bracket proach positions which lessen the deflection oi the yarn, and as it moves upwards to lengthen the:

balloon the two guides approach positions which increasethe deflection of the yarn.

5.- A yarn-tensioning-device for a yarn throw-- ing machine comprising a two-part carrier memher having its two parts shaped and pivotally connected together as complementa'ryjaws, a laterally-extending pivot pin-for those jaws a bifurcated bracket pivotally mountedon such against the counterweight lessening their deflection oftheyarn, whilst reverse movement -due to theicounterw'eight increases the defle'ction'of theya'rn. l

- HERBERT LABCHQ.

and eirtendins upwardlytherefromand a supporting member also held in'the bracket, extend-- 'ing forwardly to support -the balloonguide, and; 

